Handheld wireless communication devices of compact dimensions are often preferred, so as to provide users with a measure of convenience, portability, unobtrusiveness, and ease of maneuverability. In furtherance of these objectives, substantial efforts have been directed towards reducing the spatial volume occupied by semiconductor chips, resistors, capacitors, and circuit substrates. Nonetheless, the amount of space required for an antenna covering a specified frequency range has remained relatively constant. For many practical applications, antenna designs occupy an undesirably large area or volume.
An antenna is comprised of one or more elements, which for the purposes of this description can include any combination of active and parasitic radiators, reflectors and directors. Antenna elements also include loading devices and other components providing signal propagation capabilities for transmission and reception.
In addition to size, another shortcoming of existing antenna designs is that they are fixedly mounted to the handheld wireless communication device, yet no mechanism is provided for changing the radiation pattern of the antenna, such as in response to movement of the communication device. Accordingly, it is desirable to have an antenna of compact dimensions that includes a radiation pattern adjustment mechanism.
One area of growing interest for wireless communications is the use of variable input (VI) arrangements for tracking multiple signals, for example, those coming from different satellites. Typically, variable input communications are conducted using a plurality of receiving antenna elements. One drawback to widespread application is having multiple antenna elements in small receive only devices such as satellite radios, digital video or digital audio systems. It would be desirable to provide such multiple antenna elements in a small device.